GNU Radio 2.x: gri_lfsr_15_1_0.h Source File

Main Page | Modules | Namespace List | Class Hierarchy | Compound List | File List | Namespace Members | Compound Members | File Members

# gri_lfsr_15_1_0.h

Go to the documentation of this file.

    00001 /* -*- c++ -*- */
    00002 /*
    00003  * Copyright 2004 Free Software Foundation, Inc.
    00004  *
    00005  * This file is part of GNU Radio
    00006  *
    00007  * GNU Radio is free software; you can redistribute it and/or modify
    00008  * it under the terms of the GNU General Public License as published by
    00009  * the Free Software Foundation; either version 2, or (at your option)
    00010  * any later version.
    00011  *
    00012  * GNU Radio is distributed in the hope that it will be useful,
    00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
    00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    00015  * GNU General Public License for more details.
    00016  *
    00017  * You should have received a copy of the GNU General Public License
    00018  * along with GNU Radio; see the file COPYING.  If not, write to
    00019  * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
    00020  * Boston, MA 02111-1307, USA.
    00021  */
    00022
    00023 #ifndef INCLUDED_GRI_LFSR_15_1_0_H
    00024 #define INCLUDED_GRI_LFSR_15_1_0_H
    00025
    00032 class gri_lfsr_15_1_0 {
    00033   unsigned long d_sr;           // shift register
    00034
    00035  public:
    00036
    00037   gri_lfsr_15_1_0 () { reset (); }
    00038
    00039   void reset () { d_sr = 0x7fff; }
    00040
    00041   int next_bit (){
    00042     d_sr = ((((d_sr >> 1) ^ d_sr) & 0x1) << 14) | (d_sr >> 1);
    00043     return d_sr & 0x1;
    00044   }
    00045
    00046   int next_byte (){
    00047     int v = 0;
    00048     for (int i = 0; i < 8; i++){
    00049       v >>= 1;
    00050       if (next_bit ())
    00051         v |= 0x80;
    00052     }
    00053     return v;
    00054   }
    00055 };
    00056
    00057 #endif /* INCLUDED_GRI_LFSR_15_1_0_H */